The present invention relates to an oil separator for separating oil from a gas stream, and to the use of an oil separator according to the invention in a ventilation filter for a thermodynamic retarder.
Oil separators of this type are often mounted on oil tanks or housings in which the oil flows in and out subject to function. This presents the problem of separating the amounts of oil contained in the outflowing air in the form of droplets or slugs to minimize or entirely eliminate oil emissions. The oil separator is simultaneously used to clean the air from dust and dirt particles as it enters the housing. Separators of this type are required to ensure maximum separation efficiency and minimum pressure loss.
DE 44 07 177 discloses an oil tank ventilation filter that is connected to a housing by a connecting piece and has a radial flow through a filter element. The filter element is protected by an outer casing, such that flow toward the outside occurs through the bottom of the outer casing. To prevent the separated oil from dripping toward the outside, a baffle is mounted on the inside of the outer casing, which allows the separated oil to drip into a collection trough and flow back into the tank.
A drawback in this embodiment is that the filter element is the only separation stage and thus fails to take into account that an oil-laden air stream can contain oil in different forms, e.g., as slugs or large droplets. Furthermore, the cross-sectional narrowing of the flange increases flow resistance. Since the oil is collected on the outside of the filter medium, the collected oil may slop over, e.g., in moving vehicles.